This floating wetland plant is known as Water Lettuce (Pistia Stratiotes). Overall diameter is about 6 inches across per bundle. Light green coloration and shaped like a thicker rubbery lettuce with visible reproductive system in center of plant.

Reference: https://fullserviceaquatics.com/aquatic-plants/water-lettuce-is-a-real-pistia/

Location: USF Riverfront Park, 6550 E Fletcher Ave, Tampa, FL 33617, USA

Habitat: Water lettuce is common in rivers, lakes, and ponds.

Distribution: Water lettuce is found from New York to Florida. In South America, and even in Africa where it happens to be one of the hippo's most favorite foods.

American Alligator measuring about 6 feet in total length.
Long slender body, about the size of a young adult, and had a dark charcoal coloration. No reproductive structures present.
All American alligators have the defining characteristic of a creamy colored underbelly.

Reference:
https://defenders.org/american-alligator/basic-

Location: Riverfront Park, 6550 E Fletcher Ave, Tampa, FL 33617, USA

Habitat: Alligators thrive in freshwater. Ponds, marshes, wetlands, rivers, and of course swamps.

Distribution: American alligators can be found in Florida, southern Texas, Louisiana and parts of North and South Carolina, Georgia and Alabama.